The present invention relates to a gas regulator and, more particularly, to a gas regulator for controlling flow of gas.
FIG. 4 shows a conventional gas regulator including a pressure adjusting cap 1′, an upper cover 2′, a screw rod 3′, a pressure adjusting block 4′, a spring 5′, a diaphragm assembly 6′, a lever 7′, a base spring 8′, and a body 9′. A fastener 12′ is extended through a hole 11′ in an upper end of the pressure adjusting cap 1′ and engaged with a screw hole 31′ of the screw rod 3′. The upper cap 2′ includes a circular hole 21′, an exhaust 22′, and a plurality of longitudinal passageways 23′. The screw rod 3′ includes a head 30′ extending beyond the circular hole 21′. The exhaust 22′ is in communication with an interior of the upper cover 2′ to allow passage of air into or out of the upper cover 2′. The pressure adjusting block 4′ is movably received in and limited by the passageways 23′ defined in an inner periphery of the upper cover 2′ such that the pressure adjusting block 4′ can only move upward or downward along the passageways 23′. The screw rod 3′ includes an outer thread 32′, a bottom hole 33′, and a limiting member 34′. The fastener 12′ engages the upper end of the screw hole 31′ in the head 30′ with the pressure adjusting cap 1′ as an integral member. The pressure adjusting block 4′ is polygonal, with the pointed sections of the pressure adjusting block 4′ received in and restrained by the passageways 23′, avoiding rotation of the pressure adjusting block 4′. The pressure adjusting block 4′ includes a central inner thread 41′ threadedly engaged with the outer thread 32′ of the screw rod 3′. Since the pressure adjusting block 4′ is not rotatable, when the pressure adjusting cap 3′ is rotated, the pressure adjusting block 4′ moves upward or downward along the passageways 23′ due to threading connection between the inner thread 41′ and the outer thread 32′. To avoid disengagement of the pressure adjusting block 4′ during the downward movement, the limiting member 34′ includes a threaded shank 341′ that is threadedly engaged in the bottom hole 33′ in the bottom of the screw rod 3′. The spring 5′ is a compression spring having an upper end abutting the pressure adjusting block 4′ and a lower end abutting the diaphragm assembly 6′. Thus, when the pressure adjusting block 4′ is moved upward or downward by rotating the pressure adjusting cap 1′, the spring 5′ presses against the diaphragm assembly 6′ to different extents. The diaphragm assembly 6′ includes an axle 60′, a washer 61′ riveted to a top of the axle 60′, a pressing board 62′, and a diaphragm 63′ made of rubber. A flange on outer periphery of the axle 60′ is in sealing contact with the diaphragm 63′ due to pressing by the washer 61′ and the pressing board 62′. A portion of the outer periphery of the diaphragm assembly 6′ not pressed against by the pressing board 62′ is sandwiched by the upper cover 2′ and the body 9′ for sealing purposes to avoid leakage of gas. The axle 60′ includes an annular groove 601′ in which the lever 7′ is engaged. The lever 7′ includes a slot 71′, a pin hole 72′, and a seal 73′. The slot 71′ includes a larger section through which the axle 60′ extends, such that the annular groove 601′ of the axle 60′ is engaged with the smaller section of the slot 71′. Thus, the lever 7′ can be driven by the axle 60′. A pin 74′ is extended through the pin hole 72′ to fix the lever 7′ to the body 9′. Thus, the seal 73′ at the bottom of the lever 7′ can sway to open or close a gas inlet 92′ of the body 9′. The base spring 8′ is a compression spring having an upper end abutting the lever 7′ and a lower end abutting a limiting groove 91′ of the body 9′. Thus, the base spring 8′ can assist in reliable closing of the gas inlet 92′ of the body 9′ by the seal 73′ of the lever 7′. The body 9′ further includes a gas outlet 93′, two opposite fixed seats 94′, a base 95′, a pressure reducing chamber 96′, and an annular wall 97′. The gas inlet 92′ and the gas outlet 93′ allow gas to flow into a gas stove. Two ends of the pin 74′ are fixed by the fixed seats 94′. The diaphragm 63′ and the upper cover 2′ are mounted to the base 95′ in sequence. The annular wall 97′ is processed by a machine to bend and deform inward for fixing the diaphragm 63′ and the upper cover 2′. Since the diaphragm 63′ and the base 95′ are completely sealed, a pressure reducing chamber 96′ is formed between the diaphragm 63′ and the body 9′. When the gas in the pressure reducing chamber 96′ flows outward due to use of the gas stove (namely, the pressure in the pressure reducing chamber 96′ drops), the spring 5′ pushes the diaphragm assembly 6′ and the axle 60′ downward. The lower end of the axle 60′ actuates the lever 7′ and, thus, causes the seal 73′ to sway upward, which, in turn, opens the gas inlet 92′ to allow the high-pressure gas to flow into the pressure reducing chamber 96′. The diaphragm assembly 6′ and the axle 60′ are moved upward when the pressure in the pressure reducing chamber 96′ increases. The lower end of the axle 60′ actuates the lever 7′ and, thus, causes the seal 73′ to sway downward. The amount of gas flowing through the gas inlet 92′ into the gas stove is reduced under the action of the base spring 8′. By repeated movements in a relatively short period of time, the pressure of the gas outputted to the gas stove can be maintained in a certain range. In a case that the pressure of the gas flowing from the pressure reducing chamber 96′ to the gas stove is not proper, the user can only rotate the pressure adjusting cap 1′ to cause rotation of the screw rod 3′ engaged with the pressure adjusting cap 1′. Since the pressure adjusting block 4′ threadedly engaged with the screw rod 3′ is not rotatable, the pressure adjusting block 4′ is moved upward or downward along the passageways 23′ due to threading connection between the inner thread 41′ and the outer thread 32′. Thus, the diaphragm assembly 6′ and the axle 60′ are pressed against by the spring 5′ to different extents to change the pressure of the gas flowing from the pressure reducing chamber 96′ to the gas stove. However, the gas regulator of FIG. 4 can not be manually operated to shut off the gas, nor can the flow of the gas be adjusted.
FIG. 5 shows another conventional gas regulator proposed to solve the disadvantages of the conventional gas regulator of FIG. 4. Specifically, the gas regulator of FIG. 5 includes a knob 1″, an upper cover 2″, a return spring 3″, a rotating block 4″, a movable block 5″, a pressure adjusting spring 6″, a diaphragm assembly 7″, a body 8″, and an inlet tube 9″. The knob 1″ includes an inner tube 10″, an engagement groove 11″, and a protrusion 12″. The upper cover 2″ includes a circular tube 21″, a circular hole 22″, and a semi-circular, inclined slope 23″ having an upper stop end 231″ and a lower stop end 232″. The rotating block 4″ includes an engagement portion 41″ engaged with the engagement groove 11″ of the knob 1″, a limiting block 42″ for preventing disengagement of the rotating block 4″ from the knob 1″, an inner thread 43″, a screw rod 44″ having an outer thread 441″ threadedly engaged with the inner thread 43″, a bottom hole 45″, and a protruded portion 46″. The diaphragm assembly 7″ includes a pressing block 70″, a diaphragm 71″ mounted to a top of the pressing block 70″, and a pressing board 72″. The body 8″ includes a screw hole 81″ for threadable receipt of the inlet tube 9″, a gas outlet 82″, a pressure reducing chamber 83″ in communication with the gas outlet 82″, and an annular wall 84″ that can be bent to fix the body 8″ and the upper cover 2″. The inlet tube 9″ includes a gas inlet 91″ and a passageway 92″ in communication with the gas inlet 91″ and having an inner thread 93″ threadedly engaged with a valve body 94″ to which a seal ring 95″ is mounted for preventing leakage of the gas. The valve body 94″ includes a passage 941″ in communication with the gas inlet 91″ and the gas outlet 82″. A compression spring 942″ is mounted around a valve stem 943″ received in the passage 941″. The valve stem 943″ includes a plug 944″ for closing the passage 941″. The engagement portion 41″ of the rotating block 4″ is engaged with the engagement groove 11″ and the protrusion 12″ of the knob 1″ to allow joint movement. The return spring 3″ is mounted around the inner tube 10″ of the knob 1″, with an upper end of the return spring 3″ abutting an inner face of a top end of the knob 1″, and with a lower end of the return spring 3″ abutting top faces of the upper and lower stop ends 231″ and 232″ of the upper cover 2″. The movable block 5″ is received in the bottom hole 45″, with an upper end of the movable block 5″ abutting the bottom of the screw rod 3″, and with a lower end of the movable block 5″ abutting an upper end of the compression spring 6″. A lower end of the compression spring 6″ abuts the diaphragm assembly 7″. The body 8″ is aligned with a bottom of the upper cover 2″, and the annular wall 84″ of the body 8″ is processed by a machine to bend and deform inward for fixing the body 8″ and the upper cover 2″. After fixing of the body 8″ and the cover 2″, the upper end of the diaphragm 7″ abuts the lower end of the compression spring 6″, and the upper end of the compression spring 6″ abuts the lower end of the movable block 5″. Since the upper end of the movable block 5″ abuts the lower end of the rotating block 4″ coupled to the upper cover 2″ and the knob 1″ and since the return spring 3″ is mounted between the upper cover 2″ and the knob 1″, the protruded portion 46″ of the rotating block 4″ is located above (but not right above) the semi-circular, inclined slope 23″ under the action of the return spring 3″.
In use, the knob 1″ is pressed and rotated to move the protruded portion 46″ to a position right below the slope 23″, with the upper face of the protruded portion 46″ abutting the bottom face of the upper stop end 231″ of the semi-circular inclined slope 23″. At the same time, the rotating block 4″ securely engaged with the knob 1″ is moved downward due to downward movement of the knob 1″, pushing the movable block 5″, the pressure adjusting spring 6″, and the diaphragm assembly 7″ downward. Thus, the pressing block 70″ of the diaphragm assembly 7″ abuts the upper end of the valve stem 943″. The knob 1″ is further rotated. Since the upper face of the protruded portion 46″ moves from the upper stop end 231″ to the lower stop end 232″ along the bottom face of the semi-circular, inclined slope 23″, the rotating block 4″ securely engaged with the knob 1″ is also rotated downward to its lowest position. At the same time, the pressing block 70″ causes downward movement of the valve stem 943″ to its lowest position, such that the plug 944″ has the largest spacing to the passage 941″. The high-pressure gas from the gas inlet 91″ passes through the passageway 92″ and the passage 941″ into the pressure reducing chamber 83″ under the maximum flow and then exits the gas outlet 82″. In a case that the knob 1″ is turned to a position such that the upper face of the protruded portion 46″ abuts the bottom face of the semi-circular inclined slope 23″ in a location between the upper and lower stop ends 231″ and 232″, the spacing between the plug 944″ and the passage 941″ is half of the maximum spacing. Thus, the high-pressure gas from the gas inlet 91″ passes through the passageway 92″ and the passage 941″ into the pressure reducing chamber 83″ under the half flow. On the other hand, if the knob 1″ is rotated in a reverse direction such that the protruded portion 46″ is located above (but not right above) the semi-circular, inclined slope 23″, due to provision of the return spring 3″ between the upper cover 2″ and the knob 1″, the rotating block 5″ is moved upward without pushing the pressing block 70″. The valve stem 943″ moves such that the plug 944″ closes the passage 941″ to prevent the gas from entering the pressure reducing chamber 83″. Since diameter of the passage 941″ must receive the valve stem 943″ such that a large gap exists between an inner periphery of the passage 941″ and the valve stem 943″, when the pressing block 70″ presses against the valve stem 943″, the valve stem 943″ will wobble and decline in a direction indicated by an arrow A in FIG. 5, and the movement of the valve stem 943″ is inaccurate, adversely affecting control of the flow of the gas. Thus, a need exists for accurately controlling the flow of the gas and accurately closing and opening the passage to increase the efficiency.